Valve-controlling mechanism for internal-combustion engines.



L. H. COBB.

- VALVE CONTROLLING MECHANISM FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED JAN.3I. I9I3.

PatentedSept. 28, 1915.

ITZDBTQFZ'OU Lymanff 50/51). 5 W 6 67m nnrrnn ssraWnia rforrren LYMAN H.COBB, OF FITCH BURG, MASSACHUSETTS, ASSIGNOR TO MARY ELIZABETH JOHNSON,TRUSTEE, 0F FITCHBURG, MASSACHUSETTS.

VALVE-CONTROLLING MECHANISM FOR INTERNAL-COMBUSTION ENGINES.

T0 allwhom it may) concern: 1

Be it known that L'LYMANH. COBB, a citizen of, the .United States,residing at F itchburg. in the county of Worcester and I Commonwealth.of Massachusetts, have invented a new and useful Improvement nValve-Controlling Mechanism for InternaL' Combustion Engines, of whichthe following, together with the accompanying drawing, is aspecification. I

My invention relates to valve controlling mechanism and moreparticularly to mechanism for controlling the operation of the intakeand exhaust valves of internal combustion engines, the invention beingparticularly applicable to engines designed for motorcycles. 1

One object. of the invention is to providea valve controlling mechanismwhich shall be extremely simple so as to be of lightweight and, further.so as not to get out of orde easily. It is obvious that these featuresare particularly desirable in connection with motorcycles.

One form of the invention will be described in connection with theaccompanying drawing, in which- Figure 1 is a side elevation of thecrank case and cylinders of a motorcycle engine, a portion of the crankcase being, removed to show the valve controlling mechanism asconstructed in accordance with my invention; Fig. 2 is a sectional viewon the line 2-2 of Fig. 1; and Fig. 3 is a sectional view on the line 33of Fig. ,1.

Like reference characters refer to'similar parts in the differentfigures. i

The crank case 1 and the cylinders 2 and 3 are rigidly joined in anysuitable manner, the cylinders being set .apart about the crank shaft Anintake valve stem 4 and an exhaust valve stem 5 for the cylinder 2'areoperated by tappets 6 and 7 respectively. An intake valve stem 8 and anexhaust valve stem 9 of the cylinder 3 are similarly operated by tappets10 and 11 respectively. The valve stems are provided with spiral springs12 confined between shoulders 13 on: the valve stems and the surfaces ofthe cylinders and tending to. maintain their respective valves in closedposition.

The tappet'? reciprocates in a bushing 14% mounted in the crank case.the tappet being] held by the bushing in alinement with the valve stem 5operated thereby. Each of the Specification of Letters Patent.

Patentedsept. 28,1915.

Application filed January 31, 1913. Serial No. 745,325.

other three tappets 6, l0 and 11 are similarly mounted in bushingscarried by the crank case.

Theupper ends of the tappets 6. 7, 10 and tained'in any desiredadjustment by lock nuts carried thereby and screwed down againsttheends'of the tappets. The adjusting screws serve to adjust the effectivelengths of the 'tappets so as to move their respective valves throughthe proper distances. l

The lower end of each of the tappets engages the external face orperiphery of a ring shaped member 15, the periphery of this ring shapedmember being provided with cams 16 and 17 for operating" the tappets 6and 7 respectively and with cams 18' and 19 for operating: the tappets10 and 11 respectively. The cams are, of course,

located at slightly different distances from the edge of the ring-shapedmember 15 so thattheir paths will not coincide, the lower ends of thetappets being similarly posi tioned so that each may lie normallywithinthe path of the proper camv In order to reduce friction. the camengaging ends of the tappets are provided with antifriction roll:ers'20. 2

One edgeof the internalface of the ringshaped member 15 18 provided withgear .teeth 21 and the other edge is finished to form cylindricalbearing: surface 22. The crankcase 1 carries a cylindrical fianze 23,the flange being" preferably integral with the crank case. The externalcylindrical face of this flange is finished to provide a bearingsurfaceQ-i: to fit within thebearing surface 22, the flange 23 thusforming a bearing for the ring-shaped member 15 to rotate upon. Thedriving shaft 25, mounted in a suitable bearing): 26 formed in the crankcase. drives a pinion 27 whichengzages thev teeth 21 of therinQJ-shaped. member 15. It will be seen that the ring-shaped member 15is really an internal gear wheel carryingthe cams 16, 17, 18 and 19 onitsperipherv and driven by the pinion 27, The pinion 27 is-securedto theshaft 25 by a screw 28 and a key 29. The

the crank case 1.

In order that objectionable differences in pressure within thecrankcase, caused by the movements of the pistons and other parts of theengine, may be prevented, the

tappet 10 is hollow, the space 31 within thetappet having communicationthrough one. side of the tappet with a pipe 32 leadingto a point outsidethe crank case, so that the space 31 within the tappet 1s always'incommunication with the outside air. Two

other openings33 are provided through another side of the tappet so asto move into enough in cross section, but the number of openings shownis preferable in order that air and other gases may, pass to and fromthe interior of the crank case with as little resistance as possible.Each time that the tappet 10 is raised by its cam 18, the openings 33will come into register with the openings 34, thus establishingcommunication between the interior of the crank case and the outside airby way of these openings, the space 31 and the pipe 32. The

tappet 10 with its cam 18 thus acts to prevent objectionable changes inpressure within the crank case, or, as it is sometimes said in'the art,it. acts as a. breather. The space 31 maybe a continuation of thethreaded opening provided for the adjusting screw 10, this ad usting.screw servingtoclose the upper end of the space 31.

The shaft 25 is driven directly by. the connecting rods of the engineand so the pinion 27 rotates once for each. complete up and down strokeof one of the pistons. In the engine shown, each piston makes two suchcomplete strokes during each cycle and, therefore, each. valve mustoperate once while its piston is making two complete strokes. For thisreason the number of teeth. on the internal gear wheel 15 is. twice asgreat as the number of teeth on the pinion 27, sothat the gear wheelwill rotate once while the pinion driving it is rotating twice.

While I have illustrated the principles of,

my invention by showing and describing the details of one form thereof,I do not wishto' be limitedto such details as it is obvious thatcertain, changes may be made within the scope of th'eappended claimswithout departing from the spirit offthe invention;

but 7 What I claim as new and desire to secure by Letters Patent is:

1. In an. internal combustion engine, a

Copies 'of this patent may be obtained for shaft journaled in saidcasing, a bearing formed on said crank casing surrounding said crankshaft and eccentric thereto, an annular member ournaled on said bearinand having an internal gear, a pinion on said crank shaft meshing withsaid internal gear, and cams on the periphery of said annular member foractuating the valves of I said cylinders.

3. An internal combustion'engine including a ring-shaped member with oneedge of its internal face provided with gear teeth and the other edge ofsaid face finished to form a cylindrical bearing surface, the externalface of said member being provided with a cam, a pinion engaging thegear teeth todrive said member and earn, a bearing engaging the bearingsurface of the ring-shaped. member to support it, and

valve-o cratin means iro'ectin normall 2": 51

into the pathv of the cam to be moved tl'iereby; V I

4. An internal combustion engine including a-crank case, a cylindricalflange carried,

by the'crank case and having its outer surface finished to form abearing, a ringshaped member having an internal bearing surface androtatably mounted upon said cylindricaliflange, the external face of theriiig shaped member being provided with a cam, valve operating meansprojecting normally, nto the path of the cam, and means for dr ving thering-shaped'member.

5. an internal combustion engine includ-.

ing a crank case, a cylindrical flange carried by the crank case andhaving itsouter surface finished to form a bearing, an internal gearwheel with its gear teeth located at one edge of its internal face, theother edge of said face being. finished to form a bearing surface to fitover the flange on the crank case, the external face of the gear wheelbeing provided with a cam, valve-operating meansdriven by the cam, and apinion to drive the gear wheel.

Dated this 24th day of January, 1913.

. LYMAN H. COBB.

Witnesses: V

NELLIE WHALEN,

PENELOPE COMERBACH.

five cents each; by addressing the Commissioner of Patents,WashingtomDfiG, 7

